Filter elements; air cleaner; assembly; and, methods

ABSTRACT

A filter cartridge, a safety element and fluid cleaner assembly are described. The fluid cleaner assembly generally includes a housing having a cover and a primary fluid cleaner section. The filter cartridge generally comprises z-filter media, arranged in a straight through configuration. Preferred cartridges include a seal gasket positioned to extend continuously around at outer perimeter of the straight through flow construction. The fluid cleaner assembly can have a precleaner positioned therein. Preferred features are described. Methods of assembly and use are also provided.

This application is a continuation of U.S. Ser. No. 12/692,114, filedJan. 22, 2010, which issued as U.S. Pat. No. 8,101,003 on Jan. 24, 2012.U.S. Ser. No. 12/692,114 is a continuation of U.S. Ser. No. 10/587,766,filed 14 May 2007, which issued as U.S. Pat. No. 7,674,308 on Mar. 9,2010. U.S. Ser. No. 10/587,766 is a National Stage application ofPCT/US2005/009813, filed 23 Mar. 2005, which claims benefit of U.S.Provisional Patent Application Ser. No. 60/556,113, filed Mar. 24, 2004.U.S. Ser. Nos. 12/692,114, 10/587,766, and 60/556,113 are incorporatedherein by reference. To the extent appropriate, a claim of priority ismade to each of the applications.

TECHNICAL FIELD

The present disclosure relates to filter constructions for filteringfluids, such as liquids or gases. This particular disclosure concerns:straight through flow filter cartridges; safety filters; assembliesemploying such filters; precleaners; and methods for use of, andassembly of, filter cartridges.

BACKGROUND

Straight through flow filters (filter elements or filter cartridges)have been used in various systems for filtering fluids such as gases orliquids. Straight through flow filters typically have an inlet face (orend) and an oppositely disposed outlet face (or end). During filtering,the fluid to be filtered flows in one direction upon entering the filterat the inlet face, and has the same general direction of flow as itexists the outlet face. Typically, a straight through flow filter isinstalled in a housing, for use. After a period of use, the filterrequires servicing, either through cleaning or complete replacement ofthe filter. A seal is necessary between the filter and a portion of thehousing in which the filter is placed in use, to ensure proper filteringof the fluid flow through the arrangement.

Improvements in straight through flow filters, their assembly and theiruse are desirable.

SUMMARY

According to the present disclosure a filter element or cartridge isprovided. The filter element or cartridge in general has a straightthrough flow construction and comprises z-filter media. The filterelement or cartridge includes a seal gasket.

A particular type of air filter cartridge is of concern, to the presentdisclosure. In general the air filter cartridge comprises: a z-filtermedia pack; a preform having a portion circumscribing the media pack,the preform including a housing seal support portion; and, a housingseal arrangement. The housing seal arrangement generally includes: ahousing seal portion secured to the housing seal support; and, a mediapack sealing portion circumscribing the media pack and sealing thepreform to the media pack. Preferably the media pack sealing portion is(molded) integral with the housing seal portion. Also, preferably, thehousing seal support portion includes a plurality of aperturestherethrough; and, the housing seal arrangement includes a seal materialextending through the seal apertures to mechanically secure the sealmaterial to the preform.

In a particular form presently disclosed techniques, a coiled z-filtermedia pack is positioned inside of a preform. The preform includes anouter side wall shell, an end grid in a core secured to the end grid andprojecting internally into the z-filter media pack, partway.Construction of this arrangement involves inserting the coiled mediapack into the preform, causing the core to push into the media pack. Asindicated, the core does not project completely through the media pack,but rather typically and preferably no more than 75% through the axiallength of the media pack, usually no more than 60%. An end of the mediapack opposite the end into which the core projects, preferably the mediapack has no central core. Preferred securing of the media pack to thepreform would be as characterized above.

Methods of preparing such filter cartridges are provided.

The features, techniques and principles disclosed can be applied to avariety of filter cartridges for a variety of uses. In the drawings, asystem is disclosed utilizing a preferred filter cartridge according tothe principles generally characterized above is provided, with theremainder of the system generally according to many of the principles inPCT application of Apr. 3, 2003 (PCT/US 03/10258, claiming priority toU.S. 60/370,438, filed Apr. 4, 2002; 60/426,071, filed Nov. 12, 2003;and Ser. No. 10/405,432, filed Apr. 2, 2003), the complete disclosuresof all four which are incorporated herein by reference.

Herein, a variety of features, arrangements and techniques are provided,that can be incorporated into air cleaner arrangements, to advantage.Selected ones of the techniques features arrangements can be utilized,to advantage. Together, a particularly preferred arrangement isprovided. However, it is not a requirement that all filter elements orassemblies must incorporate all advantageous features herein, to obtainbenefit and advantage according to the present disclosure. Theindividual features, techniques and advantages can be selected and beselectively combined, for various alternate arrangements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side perspective view of an air cleaner arrangementaccording to the present disclosure;

FIG. 2 is an exploded, perspective view of the air cleaner arrangementdepicted in FIG. 1, the precleaner, primary filter, and safety filterbeing viewable;

FIG. 2 a is an exploded, perspective view of a precleaner assemblyportion of the air cleaner arrangement depicted in FIG. 1;

FIG. 3 is an inlet end view of the air cleaner arrangement depicted inFIG. 1;

FIG. 4 is a cross-sectional view of the air cleaner arrangement depictedin FIG. 1, the cross-section being taken generally along the line 4-4 ofFIG. 3;

FIG. 5 is a schematic, perspective view of z-filter media; a type ofmedia preferably used in the primary filter cartridge of FIG. 2;

FIG. 6 is a plan view of the primary filter cartridge viewable in FIG.2; FIG. 6 being taken toward an inlet face.

FIG. 7 is a cross-sectional view of the primary filter cartridge of FIG.6, the cross-section being taken along the line 7-7 of FIG. 6;

FIG. 7A is a side, elevational view of the filter cartridge depicted inFIGS. 6 and 7;

FIG. 8 is an enlarged fragmentary view showing an interaction between agasket member mounted on the primary filter cartridge and structuralmembers on certain housing components;

FIG. 9 is a perspective view of a preform useable to form the filtercartridge of FIGS. 6-7A;

FIG. 9A is an end view of the preform depicted in FIG. 9; FIG. 9A beingtaken toward the end of the preform indicated at reference numeral 61,FIG. 9;

FIG. 9B is a cross-sectional view taken generally along line 9B-9B, FIG.9A;

FIG. 9C is a cross-sectional view taken along line 9C-9C, FIG. 9B.

FIG. 10 is a cross-sectional view of a mold arrangement including thepreform of FIG. 9 with a media pack therein, positioned in a mold forforming a housing seal arrangement of the filter cartridge depicted inFIGS. 6-7A.

FIG. 10A is a fragmentary cross-sectional view of the arrangement ofFIG. 10, taken generally along line 10A-10A thereof.

FIG. 11 is a perspective view of a safety filter usable in the aircleaner arrangement depicted in FIG. 2;

FIG. 12 is a longitudinal cross-sectional view of the safety filterdepicted in FIG. 11;

FIG. 13 is an end view of the safety filter of FIG. 11;

FIG. 14 is a side elevational view of the safety filter depicted in FIG.11;

FIG. 15 is a schematic depiction of various flute definitions;

FIG. 16 is an exploded view of a second embodiment; and

FIG. 17 is a cross-sectional view of a mold arrangement, analogous tothe mold arrangement depicted in FIG. 10, and showing an alternateembodiment of a preform.

DETAILED DESCRIPTION A. Overview

The principles herein generally are preferred features for serviceablefilter cartridges. The serviceable filter cartridges can be used in avariety of arrangements, typically as primary air filter cartridges forair cleaners. The term “serviceable” in this context, is meant to referto a filter cartridge which after a period of use is removed andreplaced, with respect to the air cleaner. The term “primary” in thiscontext is meant to refer to the filter cartridge on which a majority ofdust or other contaminant which passes through filter media in the aircleaner, is loaded.

In general, the features, techniques and principles disclosed hereinwith respect to filter cartridges can be applied in a variety ofassemblies and arrangements. The particular arrangement depicted is afilter cartridge useable, for example, in a two-stage air cleaner, theair cleaner generally being of the type generally described in PCTpublication WO 03/08464, referenced above. For this reason, othergeneral features of the air cleaner are described in detail. Further theoverall air cleaner is enhanced, by utilization of filter cartridgeaccording to the present preferred configuration.

B. Review of the Assembly of FIGS. 1-4

In general, the techniques described herein are applicable to fluidcleaners. There are generally two classes of fluid cleaners with whichthe techniques can be applied, namely liquid cleaners and gas cleaners.The embodiment depicted is specifically of an air cleaner (i.e., a typeof gas cleaner), and thus the features will be described in thiscontext. Applicability of the principles and techniques described toliquid cleaners or to cleaners of other gases, will be apparent from thegeneral descriptions.

Reference numeral 1, FIG. 1, indicates an air cleaner arrangement. Theparticular air cleaner 1 depicted is a two-stage air cleaner comprising:a housing 2, an outlet flow duct 3, and a dust ejector 4. In general,the air cleaner arrangement 1 also includes, within the housing 2, asdescribed below, a serviceable (primary) filter cartridge (element) andan optional, serviceable safety (or secondary) filter cartridge(element). Herein the term “primary” when used to refer to a filtercartridge or element, is meant to refer to a filter cartridge whichconducts majority of the filtering that occurs by passage of air throughmedia within the assembly. In this instance by “filtering” what is meantis removal of particulate material by passage of fluid flow throughmedia. The term “serviceable” in this context is meant to refer to afilter cartridge that is configured to be periodically removed andreplaced. (That is, the air cleaner can be serviced by removing onefilter cartridge and installing another.) A safety cartridge orsecondary cartridge (or element) helps to protect downstream componentsof the equipment on which the air cleaner assembly 1 is installed, forexample in case of failure of the primary filter cartridge or duringservicing of the primary filter cartridge.

Herein above, it was stated that the particular air cleaner 1 depictedis a two-stage air cleaner. By this it is meant that there was aprecleaner stage present, upstream of the serviceable primary filtercartridge. There is provided equipment that causes a first stage removalof dust or other componentry, prior to the air reaching the primaryfilter cartridge. The upstream component is generally a precleaner whichoperates without passage of the air through media, but rather uses acyclonic or centrifugal approach to dust separation.

Still referring to FIG. 1, in general the air cleaner 1 depicted is apreferred two-stage air cleaner having a cover 7, in this instance aprecleaner section 8, and a primary air cleaner section 9. Theparticular housing 2 depicted is jointed between the cover 7 and theprimary air cleaner section 9, at joint or region 11. At housing joint11, the cover 7 and the primary air cleaner section 9 can be opened orseparated, for access to an internally received filter cartridge, forservicing. Herein a step of pivoting, or in some instances evenremoving, a housing cover 7 relative to the primary filter cartridgecontaining section 9, will be referred to as a step of obtaining serviceaccess to an internally-received filter element component, oralternatively as “opening” the air cleaner 1, for example for servicing.

In general, air to be filtered enters air cleaner assembly 1 at inletend 12, by passage into individual cyclonic or centrifugal separators13, in precleaner 8. Separators of the type usable at reference 13 couldbe conventional, and a variety of types may be used, for example thosein U.S. Pat. Nos. 4,242,115 and 4,746,340, both of which areincorporated herein by reference.

The particular precleaner 8 shown can lead to advantages. Within theseparators 13, a first stage dust separation or precleaning occurs, anddust separated at this location is ejected from the precleaner 8 throughdust ejector 4, in particular through ejector tube 14 and ejector valve15. Of course, the process conducted in the precleaner 8 is not“filtering” as the term was defined above, since the dust separation inthe precleaner results from a centrifugal or cyclonic process, asopposed to a process of passing the fluid through a media. Theparticular precleaner 8 shown is described in more detail below.

As an alternative, in place of a precleaner that uses a plurality ofindividual cyclonic or centrifugal separators 13, a precleanerarrangement generally as characterized in U.S. provisional application60/512,109, filed Oct. 17, 2003, can be used. The complete disclosure ofthe 60/512,109 application is incorporated herein by reference.

Air that is passed out of the precleaner 8, into the primary air cleanersection 9, is then passed: (a) first through an internally receivedprimary filter cartridge, described in Section C below; and (b) nextthrough (optional) safety element (described in Section D below), andeventually into a clean air region for exiting air cleaner 1 throughclean air outlet duct 3. From duct 3, the clean air can be directed towhatever equipment is downstream, for example an engine air intake of aninternal combustion engine or a turbocharger.

Referring to FIGS. 1 and 2, in general cover 7 is pivotally secured onprimary air cleaner section 9 by supports 16 and over center clamps 17.Once the over center clamps 17 are released, the cover 7 can be openedrelative to the primary air cleaner section 9 of housing 2, by pivotingthe cover 7 (or precleaner 8) relative to the supports 16. Alternately,the system can be configured for complete separation of the cover 7during opening. (It is noted that in FIG. 2A, the over center clamps arenot shown, but mounts 17 a for them are.)

Referring to FIG. 1, the assembly 1 can be mounted on various machineryparts by mounting pads 19, for example using bolts. In general, aircleaner 1 will be mounted with ejector tube 14 and dust ejector 15directed generally downwardly, to facilitate dust ejection. The mountingpads 19 are shown in an example location. The specific type and locationof mounting pads will depend on the equipment to which the air cleaner 1is to be mounted, and the preference for accomplishing the downwarddirection of the ejector tube 14 and dust ejector 15. The relativelocation of the ejector tube 14, around a perimeter of the precleaner 8,is also a function of how the air cleaner 1 is to be mounted in use. Theparticular location shown, at one of the (opposite) narrower curved ends8 a of the precleaner 8, instead of one of the (opposite) sides 8 b isconvenient for many assemblies using principles according to the presentdisclosure.

Still referring to FIG. 1, the air cleaner 1 may include a pressureindicator 3 a and a connector 3 b adjacent outlet 3, for conventionaluse. The connector 3 b can provide, for example, for filtered air flowto a crank case ventilation system.

Referring still to FIG. 1, outlet 3 is a fixed stationary outlet.Alternatives are possible. With respect to this, attention is directedto FIG. 16 in which an exploded view of an alternate embodiment 400 isdepicted. Air cleaner 400 comprises precleaner 401, primary filterelement 402, optional safety element 403, housing section 404 and outlet405. The outlet 405 is swivel or pivotal piece, mounted with a snap-fitat 406 and a swivel ring 407. Thus, it can be pivoted on housing 405 foroutlet end 408 to be directed in a variety of directions.

The other components 401, 402, 403 and 404, may be analogous to the samecomponents as described in connection with the other figures.

Attention is now directed to FIG. 4, which is a fragmentarycross-sectional view of the assembly 1 depicted from the view point ofline 4-4, FIG. 3. Referring to FIG. 4, precleaner 8 is shown mounted onprimary air cleaner section 9, with internally received primary filtercartridge 22 depicted and with optional internally received safetyfilter 20 depicted.

C. A Preferred Primary Filter Cartridge

Referring to FIG. 2, the filter cartridge 22 is configured to permitstraight through flow; that is, it has a straight through flowconstruction. By the term “straight through flow,” in this context, itis meant that the fluids which flow to the filter cartridge 22, forfiltering, enter filter media 26 of the filter cartridge 22 at inlet endor face 23 in a first direction and exit from opposite outlet end orface 24 with flow in the same general direction. The term “straightthrough flow” as characterized above, is meant to specificallydifferentiate a flow in a system such as that described in WO 89/01818published 9 Mar. 1989, in which air enters a cylindrical pleated filtermember by direction against a cylindrical surface, and then exits theelement (for example through an aperture) after making an approximately90° turn.

The filter cartridge 22 has an outer sidewall or surface 25 with afilter media pack 26 that is configured to filter particulates from agas stream entering the inlet end or face 23, such that the gas streamexiting the outlet end or face 24 is at least partially clean (i.e.,free of particulates). As can be seen from FIG. 2, the filter cartridge22 includes a housing gasket or housing seal 28 which aids in inhibitingleakage between the filter cartridge 22 and portions of the housing 2 inwhich the filter cartridge 22 is installed. The preferred gasket 28extends completely, peripherally, around the outer sidewall 25 of thestraight through flow construction or cartridge 22.

As will be discussed further below, for the preferred arrangements theouter side wall or surface 25 is formed by a preformed piece (preferablya preformed molded plastic piece) or preform 25 a: (a) inside of whichfilter media pack 26 is positioned, (b) to which the filter media pack26 is sealed; and, (c) on which the housing seal 28 is secured. Thispreform 25 a, is discussed in greater detail below, in connection withthe description of FIGS. 6-7A and 9-9C at 60. The preform or preformedpiece 25 a, is sometimes referred to herein as a “shell,” or as an“element housing.” It should not be confused with the air cleanerhousing 2. Indeed, in use, the particular preform 25 a shown ispositioned to secure the media pack 25 inside of air cleaner housing 2,with housing seal 28 secured between housing portions, as discussedbelow in connection with FIG. 8.

Preferred filter media packs 26 usable in the primary element 22 of aircleaner arrangement 1 uses a type of media, described below, generallyreferred to as “z-media” or “z-filter media.” Z-filter media generallycomprises a fluted (typically corrugated or pleated) media sheet securedto a facing sheet. Typically, the facing sheet for z-filter media is anon-fluted, non-corrugated sheet. In some instances a sheet havingcorrugations extending perpendicularly to the flutes of the fluted sheetcan be used, see for example the disclosure of U.S. provisional60/543,702, filed Feb. 10, 2004 and U.S. provisional 60/543,804, filedFeb. 11, 2004, both of which are incorporated herein by reference.

In general, z-filter media is arranged to form a set of longitudinal(axial) flutes or air flow channels on one side of the corrugated orfluted media, and another set of longitudinal (axial) flow channels onan opposite side of the fluted media. The term “axial” in connectionwith the definition of the longitudinal flutes, is meant to refer to adirection of flute extensions generally between the opposite faces 23,24 of the media pack 26, typically referred to as the axial direction.

In operation, flutes of one set of flutes: are designated as inletflutes; are left open at an inlet end side, edge or face of the media;and, are sealed or otherwise folded closed at an outlet end, side, edgeor face of the media. Analogously, the flutes of a second set of flutes:are generally designated as outlet flutes; are sealed or otherwiseclosed at the inlet end side, edge or face of the filter; and, are leftopen at the outlet end side, edge or face of the media. In operation,air passes into the inlet flow face 23 of the media pack 26 by passageinto the open inlet flutes at an upstream end or face of the filtercartridge 22. The air cannot flow out of the closed ends of these inletflutes, so it must pass through the filter media into the outlet flutes.The filtered air then passes outwardly from an exit end 24 of the filtermedia pack 26, through the open ends of the outlet flutes.

A variety of shapes, i.e., outer perimeter configurations, for theprimary filter cartridge 22 can be used. The particular one used thearrangement of the drawings, is an “obround” shape. The term “obround”as used herein, is generally meant to refer to an arrangement that isnot circular in a perimeter shape of a cross-section; the referencedcross-section being taken perpendicularly to a direction of extension ofthe flutes, again sometimes referenced as the axial direction. (Ofcourse, many of the techniques described herein can be applied toelements that have a circular perimeter shape or cross-section.) Avariety of obround shapes are possible including, for example, oval andracetrack. In general both of these example obround shapes can generallybe characterized as having two opposite curved ends with sides extendingtherebetween. A “racetrack shape” generally has opposite parallel sidesextending between the two, opposite, curved ends. An oval shapegenerally has a slight curvature to the opposite sides, typically withthe opposite sides positioned as mirror images to one another.

The particular filter cartridge 22 depicted, has a generally obroundshape to both a cross-section of the outer preform or shell 25 a and across-section of the media pack 26, as will be apparent from thefollowing descriptions. Typically the ends (of the cross-sectionalshape) of the obround configuration are each semi-circular.

Referring to FIG. 5, in general the filter media pack 26 is made from atwo-layered construction 45, formed from a facing sheet 46 secured to afluted, in this instance corrugated, sheet 47. Typically, the media packis a coiled arrangement and the coiling is conducted with the facingsheet 46 directed to the outside, and the corrugated sheet 47 directedinwardly. For the particular filter media pack 26 depicted, FIG. 5, thefacing sheet 46 is a non-corrugated, non-fluted shape. In thealternative a sheet corrugated perpendicularly to the direction of theflutes of the fluted sheet 47, can be used in some instances.

Media comprising strips of two-layered construction 45 formed from afacing sheet 46 secured to a fluted corrugated sheet 47, can also beformed into a media pack by stacking the strips on one another, with anappropriate sealant bead therebetween. Such arrangements are generallyreferred to as “stacked z-filter media.” The principles described hereincan be applied to a stacked arrangement, however the embodiment shown isparticularly well adapted for use with coiled arrangements.

In general, on one side 48 of the fluted sheet 47 a first set of flutes49 is formed; and on an opposite second side 50, a second set of flutes51 is formed. In FIG. 5, edge 53 would correspond to inlet face 23, FIG.2; and, edge 54 would correspond to outlet face 24, FIG. 2. The phantomlines in FIG. 5, indicate coiling of the two-layered construction 45around itself. The solid lines indicate an outer layer of the two layersdepicted, resulting from the coiling.

In use, the first set of flutes 49 are closed adjacent an edge 54; and,the second set of flutes 51 are closed adjacent to opposite edge 53.Generally when it is said that the flutes are closed “adjacent” an edge,it is meant that they are sealed along the edge or at a position spacedfrom the edge, but generally positioned near the edge. When it is statedthat the flutes are “sealed” when “closed” it is meant that they areeither sealed by an applied sealant, or they are otherwise distortedclosed, to inhibit passage of unfiltered liquid through the ends. Avariety of techniques for sealing can be used. Typically a sealant 55 isused. A sealant can be applied as a continuous strip, between the flutedsheet 47 and the facing sheet 46. The flutes can be distorted (forexample darted), in the vicinity of one or both of the ends, toadvantage. Other techniques of sealing, not involving sealant, can beapplied. Useable techniques of flute end sealing include those describedin PCT/US03/02799, filed Jan. 31, 2003, U.S. provisional applications60/455,643, filed Mar. 18, 2003; 60/466,026, filed Apr. 25, 2003; and60/467,521, filed May 2, 2003; and PCT application filed Mar. 17, 2004,under Express Mail #EV 408495263 US and under title “Improved Processand Materials for Coiling Z-Filter Media, and/or Closing Flutes ofFilter Media; and, Products”, all of which are incorporated herein byreference.

From review of FIGS. 2 and 5, it should be apparent how the media 26functions. In general, flutes of the first set of flutes 49 are open atinlet face 23, and thus comprise inlet flutes. They would be closed attheir exit ends 54, as a result of a sealant bead or similar closure atthis location. Thus, air which enters flutes of flute set 49 at theinlet edge 53 must pass through the media 26 to escape from the inletflutes. Upon passage through the media: filtering occurs; and, air flowenters a second set of (outlet) flutes 51, at a location downstream fromthe sealant 53. Flutes of the outlet set of flutes 51 are open alongedge 54, and thus the filtered fluid stream can flow out of the media26. This type of construction is generally characterized herein asz-filter media. The z-filter media generally includes a plurality offlutes; each of having an upstream portion adjacent to an inlet flowface and a downstream portion adjacent to an outlet flow face; selectedones of the flutes being open at the upstream portion and closed at thedownstream portion; and, selected ones of the flutes being closed at theupstream portion and open at the downstream portion. The inlet andoutlet flow faces are not required to be planar, however that is atypical shape, as shown in FIGS. 4 and 7.

A variety of corrugation shapes and sizes can be utilized in the filtermedia 26. Examples include: corrugations resulting in a straight flutes,in which the flutes are parallel to each other and do not change shapefrom one end to other; straight flutes having crushed or pinched ends;and tapered flutes, in which inlet flutes gradually converge from a wideend in direction to a narrow end with adjacent exit flutes divergingfrom a narrow end to a wide end, in the same direction. Some examples ofuseable z-filter media configurations are described in the followingreferences:

-   -   1. Standard flutes are depicted in U.S. Pat. No. 5,820,646; and        U.S. Pat. No. 5,895,574.    -   2. Tapered flutes, flutes with crushed ends and other variations        in flute shapes are described in WO 97/40918, published Nov. 6,        1997.

The complete disclosures of above references (i.e., U.S. Pat. Nos.5,820,646; 5,895,524 and WO 97/40918) are incorporated herein byreference.

In general, when the media pack 26 comprises a coiled media, the coilingis of a media strip sometimes referred to as a “single facer” comprisingthe fluted media sheet 47 secured to the facing sheet 46, by a sealantbead positioned between the two. The sealant bead positioned between thefluted sheet 47 and facing sheet 46 of the single facer or mediacombination 45 is generally referred to herein as the single facer beador sealant. Typically when the resulting media combination 45 is coiled,to form the coiled media pack 26, it is coiled: with the facing sheet 46directed outwardly; and, with a second bead of sealant positionedadjacent an opposite end of the flutes from the single facer bead, alongan opposite side of the facing sheet from the single facer bead. Thissecond bead is typically referred to as a “winding bead,” since: (a) itis formed generally immediately prior to coiling or winding of the mediacombination 45; and (b) its sealing function is provided as a result ofthe winding.

When the media pack 26 is formed by coiling the media configuration 45with a winding bead thereon, a region of sealant from the winding beadis generally positioned toward an inside of the wind. The media can thenbe compressed at this region, sealing opposite sides of the winding beadmaterial in this location together, to advantage. This is described forexample in U.S. provisional application 60/467,521, filed May 2, 2003,incorporated herein by reference. It is also described in the 60/467,521application, that a urethane material can be used to advantage at thislocation. The 60/467,521 disclosure was filed as part of a PCTapplication on Mar. 17, 2004, under Express Mail #EV 408495263 US andunder title “Improved Process and Materials for Coiling Z-Filter Media,and/or Closing Flutes of Filter Media; and, Products.” The completedisclosure of this PCT application is also incorporated herein byreference.

With respect to the preferred media pack 26, of cartridge 22, FIG. 7,the winding bead would typically be position adjacent inlet face 23,with a single facer bead adjacent outlet face 24. A core 57 projects tothe media pack 26 adjacent the outlet end 24. Adjacent face 23, wherethe winding bead is located, would be less convenient location to insertthe core 57. Also this type of construction avoids the necessity of aseal adjacent outlet face 24 between the media pack 26 and core 57.

In general, when the media pack 26 is a coil, at an inside side of thecoil a lead end of the media combination 45 is present. It may bedesirable to seal this lead end closed completely across the mediacombination, with a sealant, before coiling. In some arrangements suchas a seal at this location can be avoided, due to the presence of thewinding bead adjacent end 23 closing off a central portion of the mediapack 26 adjacent inlet end 23.

Similarly, on the outside of the media pack 26, a tail end of coiledmedia combination 45 is present. This can be sealed closed with varioussealants such as polyurethane or hot melt sealants, as desired. In someinstances, the presence of the seal 28 described below, in overlap witha portion of this tail end in a region adjacent the winding bead nearface 23, can obviate the criticality of a seal at this location.

The sealant used in the single facer bead and winding bead can be thesame or different, and a variety of sealant materials can be used.Typically hot melt sealants or foamed sealants such as foamedpolyurethanes will be used. A description of sealing to form relatedmedia packs, is provided in the above incorporated U.S. provisionalapplication 60/467,521.

If the winding bead does not provide sufficient closure adjacent inletend 23, additional sealant can be added at this location in the centralportion of the media pack 26. This is also generally described in U.S.Provisional 60/467,521.

The term “corrugated” used herein to refer to structure in media, ismeant to refer to a flute structure resulting from passing the mediabetween two corrugation rollers, i.e., into a nip or bite between tworollers, each of which has surface features appropriate to cause acorrugation affect in the resulting media. The term “corrugation” is notmeant to refer to flutes that are scored and folded or otherwise formedby techniques not involving passage of media into a bite betweencorrugation rollers. However, the term “corrugated” is meant to applyeven if the media is further modified or deformed after corrugation, forexample by the folding techniques described in PCT/US03/02799,incorporated herein by reference.

Corrugated media is a specific form of fluted media. Fluted media ismedia which has individual flutes (for example formed by corrugating orfolding) extending thereacross.

In general, the corrugated sheet 47, FIG. 5 is of a type generallycharacterized herein as having a regular, curved, wave pattern of flutesor corrugations. The term “wave pattern” in this context, is meant torefer to a flute or corrugated pattern of alternating troughs andridges. The term “regular” in this context is meant to refer to the factthat the pairs of troughs and ridges alternate with generally the samerepeating corrugation (or flute) shape and size. (Also, typically eachtrough is substantially an inverse of each ridge). The term “regular” isthus meant to indicate that the corrugation (or flute) pattern comprisestroughs and ridges with each pair (comprising an adjacent trough andridge) repeating, without substantial modification in size and shape ofthe corrugations along at least 70% of the length of the flutes. Theterm “substantial” in this context, refers to a modification resultingfrom a change in the process or form used to create the corrugated orfluted sheet, as opposed to minor variations from the fact that themedia sheet is flexible. With respect to the characterization of arepeating pattern, it is not meant that in any given filterconstruction, an equal number of ridges and troughs is necessarilypresent. The media could be terminated, for example, between a paircomprising a ridge and a trough, or partially along a pair comprising aridge and a trough. Also, the ends of the troughs and ridges may varyfrom one another. Such variations in ends are disregarded in thedefinitions.

In the context of the characterization of a “curved” wave pattern ofcorrugations, the term “curved” is meant to refer to a corrugationpattern that is not the result of a folded or creased shape provided tothe media, but rather the apex of each ridge and the bottom of eachtrough is formed along a radiused curve. A typical radius for suchz-filter media would be at least 0.25 mm and typically be not more than3 mm.

An additional characteristic of the particular regular, curved, wavepattern depicted in FIG. 5, for the corrugated sheet 47, is that atapproximately a midpoint between each trough and each adjacent ridge,along most of the length of the flutes, is located a transition regionwhere the curvature inverts.

A characteristic of the particular regular, curved, wave patterncorrugated sheet shown in FIG. 5, is that the individual corrugationsare generally straight. By “straight” in this context, it is meant thatthrough at least 70%, typically at least 80% of the length betweenopposite edges 53, 54, the troughs do not change substantially incross-section. The term “straight” in reference to corrugation patternshown in FIG. 5, in part distinguishes the pattern from the taperedflutes of corrugated media described in FIG. 1 of WO 97/40918, thecomplete disclosure of which is incorporated herein by reference. Thetapered flutes of FIG. 1 of WO 97/40918 would be a curved wave pattern,but not a “regular” pattern, or a pattern of straight flutes, as theterms are used herein.

For the particular arrangement shown herein in FIG. 5, the parallelcorrugations are generally straight completely across the media, fromedge 53 to edge 54. Straight flutes or corrugations can be deformed orfolded at selected locations, especially at ends. Modifications at fluteends are generally disregarded in the above definitions of “regular,”“curved” and “wave pattern.”

In general, the filter media is a relatively flexible material,typically a non-woven fibrous material (of cellulose fibers, syntheticfibers or both) typically including a resin therein, sometimes treatedwith additional materials. Thus, it can be conformed or configured intothe various folded or corrugated patterns, without unacceptable mediadamage. Also, it can be readily coiled or otherwise configured for use,again without unacceptable media damage. Of course, it must be of anature such that it will maintain a corrugated or folded configuration,during use.

In the corrugation process, an inelastic deformation is caused to themedia. This prevents the media from returning to its original shape.However, once the tension is released the flute or corrugations willtend to spring back, recovering only a portion of the stretch andbending that has occurred. The facing sheet is often tacked to thefluted sheet, to inhibit this spring back.

Also, in general, the media contains a resin. During the corrugationprocess, the media can be heated to above the glass transition point ofthe resin. When the resin then cools, it will help to maintain thefluted shapes.

Both of these techniques are generally known in practice, with respectto the formation of corrugated media.

An issue with respect to z-filter constructions relates to closing ofthe individual flute ends. Typically a sealant or adhesive is provided,to accomplish the closure. As is apparent from the discussion above, intypical z-filter media, especially that which uses straight flutes asopposed to tapered flutes, large sealant surface areas (and volume) atboth the upstream end and the downstream end are needed. High qualityseals at these locations are critical to proper operation of the mediastructure that results. The high sealant volume and area, creates issueswith respect to this.

Attention is again directed to FIG. 5, in which a z-filter mediaconstruction 26 utilizing a regular, curved, wave pattern corrugatedsheet 47, and a non-corrugated flat sheet 46, is depicted. A distance(D1), defines the extension of flat media 46 in a region underneath agiven corrugated flute. A length (D2) of the arcuate media for acorrugated flute, over the same distance D1 is of course larger than D1,due to the shape of the corrugated flute. For a typical regular shapedmedia used in fluted filter applications, a linear length D2 of thefluted media between points of contact with the non-fluted media willgenerally be at least 1.2 times D1. Typically, D2 would be within arange of 1.2-2.0, inclusive. One particularly convenient arrangement forair filters has a configuration in which D2 is about 1.25-1.35×D1. Suchmedia has, for example, been used commercially in Donaldson Powercore™Z-filter arrangements. Herein the ratio D2/D1 will sometimes becharacterized as the flute/flat ratio or media draw for the corrugatedmedia.

In the corrugated cardboard industry, various standard flutes have beendefined. For example the standard E flute, standard X flute, standard Bflute, standard C flute and standard A flute. FIG. 15, attached, incombination with Table A below provides definitions of these flutes.

Donaldson Company, Inc., (DCI) the assignee of the present disclosure,has used variations of the standard A and standard B flutes, in avariety of filter arrangements. These flutes are also defined in FIG. 15and Table A.

TABLE A (Flute definitions for FIG. 20) DCI Flute/flat = 1.52:1; TheRadii (R) are as follows: A R1000 = .0675 inch (1.715 mm); R1001 = .0581inch (1.476 mm); Flute: R1002 = .0575 inch (1.461 mm); R1003 = .0681inch (1.730 mm); DCI Flute/flat = 1.32:1; The Radii (R) are as follows:B R1004 = .0600 inch (1.524 mm); R1005 = .0520 inch (1.321 mm); Flute:R1006 = .0500 inch (1.270 mm); R1007 = .0620 inch (1.575 mm); Std.Flute/flat = 1.24:1; The Radii (R) are as follows: E R1008 = .0200 inch(.508 mm); R1009 = .0300 inch (.762 mm); Flute: R1010 = .0100 inch (.254mm); R1011 = .0400 inch (1.016 mm); Std. Flute/flat = 1.29:1; The Radii(R) are as follows: X R1012 = .0250 inch (.635 mm); R1013 = .0150 inch(.381 mm); Flute: Std. Flute/flat = 1.29:1; The Radii (R) are asfollows: B R1014 = .0410 inch (1.041 mm); R1015 = .0310 inch (.7874 mm);Flute: R1016 = .0310 inch (.7874 mm); Std. Flute/flat = 1.46:1; TheRadii (R) are as follows: C R1017 = .0720 inch (1.829 mm); R1018 = .0620inch (1.575 mm); Flute: Std. Flute/flat = 1.53:1; The Radii (R) are asfollows: A R1019 = .0720 inch (1.829 mm); R1020 = .0620 inch (1.575 mm).Flute:

Of course other, standard, flutes definitions from the corrugated boxindustry are known.

In general, standard flute configurations from the corrugated boxindustry can be used to define corrugation shapes or approximatecorrugation shapes for corrugated media. Comparisons above between theDCI A flute and DCI B flute, and the corrugation industry standard A andstandard B flutes, indicate some convenient variations.

Referring again to FIG. 2, the preferred (primary) filter cartridge 22is serviceable. By the term “serviceable” in this context, it is meantthat the filter cartridge 22 can be removed from the air cleanerassembly 1, and either be refurbished or replaced. In typical systems,the filter element 22 is periodically replaced, during a servicingoperation, by installation of a new replacement cartridge.

The particular, preferred, filter cartridge 22, FIG. 7 comprises thefollowing components: preform (shell) 25 a; media pack 26; centerpieceor core 57, receiver 58, grid 59; and, seal or gasket member 28. (Thegrid 59 is more readily viewed in FIG. 2.) The preferred seal member 28is generally positioned to completely circumscribe the media pack 26 andthus to separate the opposite flow faces 23, 24 of the media pack 26from one another, with respect to flow around media pack 26. For theparticular arrangement depicted, the seal member 28 is positioned tocompletely circumscribe the media pack 26, by being mounted on thepreform 25 a. For the particular, preferred, arrangement shown, the sealmember 28 is positioned with axial seal surface 28 a positioned within adistance no greater than 15 mm of, and preferably within a distance nogreater than 8 mm of, inlet face 23, although alternatives are possible.

It is noted that in the figures, the main body or straight through flowconstruction of the media pack 26 is shown schematically, in thecross-sections. That is, flute detail is not depicted. As to flutedetail, it is not shown in any figures other than the example of FIG. 5,for convenience. As indicated previously, a variety of flute shapes canbe used. Examples depicting the ends of a z-filter element, and sealingat those ends, are provided in the drawings of U.S. Des. 396,098; U.S.Pat. No. 6,190,432; U.S. Des. D450,827; U.S. Pat. No. 6,235,195; U.S.D437,402 and U.S. D450,828, all 6 of these references being incorporatedherein by reference.

Referring specifically to FIG. 6 and the cross-section shown in FIG. 7,regions 26 a show where the media pack 26 has been cut in cross-section,to provide the drawing of FIG. 7. Region 26 b indicates a region wherethe cross-section line 7-7, FIG. 6, is positioned between layers of thewound media pack 26, with the surface viewable at 26 b being acorrugated surface. A cross-section similar to FIG. 7 results, when thecross-section line, FIG. 6, is across coiled layers at the oppositecurved ends, but between layers through the center region.

As discussed in greater detail below, in general core 57 is positionedto separate layers of wound media, in which each layer comprises afluted sheet secured to the non-fluted sheet.

Referring to FIGS. 6-7A, for the preferred embodiment shown the preform(shell) 25 a, core 57, receiver 58 and grid 59 are all integral with oneanother. By “integral” in this context, it is meant that the partsidentified cannot be separated from one another without damage to thedefined unit. Collectively, these identified parts comprise preferredpreform 60. The preform 60 is prepared before the cartridge 22 isassembled. The cartridge 22 is typically assembled by inserting themedia pack 26 and the preform 60 into a mold and molding the seal 28 inplace. This is described in greater detail below.

Still referring to FIGS. 6-7A, preferably the preform 60 comprises amolded plastic material, such as a polypropylene. An example of auseable material would be a 25% glass-filled, 10% mica filled,polypropylene; such as a Thermofil polypropylene or an Adellpolypropylene.

Referring to FIGS. 9-9C, preform 60 includes opposite ends 61, 62 withside wall 63 extending therebetween. Adjacent end 61, the side wall 63has an outward funnel transition portion 64, FIG. 9B, with housing sealsupport 65, comprising radially outwardly directed seal support portionor lip 65 a thereon. Lip 65 a has seal flow apertures 66, FIG. 9A,therethrough, for use as described further below. In general housingseal support 65 will generally be characterized as radially directed,since it is directed radially outwardly from a longitudinal axis 67 ofthe preform 60, FIG. 9B.

As indicated below in connection with the description of FIGS. 10, 10A,funnel transition portion 64 opens up a space into which sealant canflow, during assembly. Preferably at outer edge 64 a, FIG. 9C, thetransition portion 64 has spread outwardly sufficiently far, to create agap for convenient sealant flow therein during assembly.

In extension between regions 71 and 68, the side wall 63 can have aslight downwardly (or inwardly) directed taper, for convenience.

In preferred arrangements, the side wall 63 will be impermeable alongits length, although alternatives are possible. Also preferably the sidewall 63, in combination with the seal 28, will extend at least theentire axial length of the media pack 26, although alternatives arepossible.

At end 62, grid work 59 is provided in extension across opening 70. Thegrid work 59 may have a variety of shapes. The particular shape provided(FIG. 9A) comprises parallel cross pieces 72, center cross piece 73, anddiagonal cross pieces 74. In general, the grid work 59 is positioned tosupport the outlet face 24 of the media pack 26, FIG. 7. The grid work59 inhibits media telescoping.

The center cross piece 73 defines a central, elongate, hollow receiver75 therein, forming receiver 58, FIG. 7. The receiver 75 preferably hasan outside aspect ratio (external length L FIG. 9A over external width WFIG. 9A) of at least 3:1, preferably at least 5:1 most preferably withinthe range of 6:1 to 10:1. Typically and preferably the external width W,FIG. 9A, is no greater than about 65%, preferably no greater than about50%, of a longer dimension of a media pack cross-section.

Referring to FIGS. 9B and 9C, preferably the receiver 75 comprises aportion of a central core 76 including receiver 75 and non-hollowcentral blade 78 thereon. Also, preferably a divider 79 is provided inreceiver 75 (FIG. 9B) to divide the receiver 75 into two sides 75 a and75 b. Preferably each side extends in depth, inwardly from edge 80 toend 81 of at least 10 mm, preferably not more than 35 mm. Typical depthfor each side would be on the order of about 15 mm to 28 mm. Preferablythe shape of each side is as shown in FIG. 9B.

Referring to FIGS. 6 and 7, outside surfaces of receiver 75 comprise acore projecting into coiled media pack 26. Typically, the coiled mediapack 26 would be formed into coil, and then be inserted over receiver75. That is, in typical assembly the media pack 26 would not be coiledwith core 76 in position. Rather the media pack 26 would firstconstructed in its coiled form, then would be inserted into interior 60a of preform 60, through end 61, and continue to be pushed inwardly topush the blade 57 (78) between layers of the media pack 26, guiding core75 into position. The somewhat triangular shape and relative thinness ofblade 78, FIG. 9B, facilitate this assembly.

More specifically, extending from inner end 75 c (FIGS. 9B and 9C) ofreceiver 75, axially inwardly of shell 25 a is provided central vane orblade arrangement 78. The blade 78 preferably comprises a non-hollow,triangularly shaped blade 78 a preferably no more than 3.0 mm thickbetween regions 75 c and 78 b; and no more than 2 mm thick at tip 78 a.Typically adjacent region 75 c the blade 78 is about 2 mm thick, and attip 78 b it is about 1.0-1.5 mm thick (for example 1.3 mm) with a taperin between. The relatively thin, non-hollow, blade 78 facilitates inpushing media pack 26 into shell 25 a with a portion around receiver 75.The blade 78 is preferably triangular in shape, with rounded tip 78 aopposite receiver 75.

Preferably blade arrangement 78 projects inwardly of media pack adistance from outlet end 24 at least 30% of axial length of the mediapack, typically at least 40% of this length. Preferably blade 78 doesnot extend further than 75% of the axial length of the media pack,typically not more than 60% of this length, and thus blade 78 endsspaced from opposite end surface 23 of the media pack 26.

FIG. 17 shows the filter cartridge 22 with an alternate embodiment of apreform 360. The particular arrangement in FIG. 17 shows the filterelement 22 within a mold arrangement 397, to be described further below.The filter cartridge 22 is shown in cross-sectional view and analternate central vane or blade arrangement 378 can be seen. The blade378 facilitates in pushing the media pack 26 into the shell 325 a. Theblade 378 is preferably triangular in shape, with a rounded tip or apex378 b.

The blade 378 of FIG. 17 differs from the blade 78 of FIG. 9 b in thatthe apex 378 b is offset from the central axis 67. That is, the apex 378b is located off to the side of the axis 67. The blade 378 has thegeneral shape of a right triangle, rather than the appearance ofequilateral or isosceles triangle of FIG. 9. The blade 378 generally hasthe same thicknesses and depth of penetration into the media 26 as theblade 78. The blade 378 is formed with the apex 378 b offset from thecentral longitudinal axis 67 for ease and convenience of pushing theblade 378 between layers of the media pack 26. When the apex 378 b isoffset from the central longitudinal axis 67, the blade 378 first entersbetween layers of media 26 that are closer to the turn in the coiledmedia pack 26. At the portion of the turn in the coiled media pack, thelayers of media 26 are not as tightly packed together as, for example,the very center of the media pack, and this creates a larger gap betweenlayers of media which facilitates an easier insertion of the blade 378between the layers of the coiled media.

Attention is now directed to FIG. 7, in which the seal arrangement 28 isshown secured to lip or flange 65 (i.e., housing seal support) ofpreform 60. This is also shown in exploded view in FIG. 8.

Referring to FIG. 8, seal 28 is molded directly to the lip or support65. Further, an integral portion 90 of seal 28 is molded directly to themedia pack 26 at 91, sealing the seal 28, preform 25 a and media pack 26together, at this location. The seal 91 is preferably directly to thefacing sheet 46 and preferably completely around the media pack 26. Theseal 91 also preferably starts on a portion of the media pack 26adjacent one of the flow faces, in this instance flow face 23.Preferably the seal 28 includes no portion extending over a flow face.

Referring to FIG. 8, seal 28 is an axial pinch seal, with respect to thehousing 2. In particular, it is pinched between sections 7 and 9 of thehousing, in particular between housing extensions 9 a and 7 a. Typicallythe seal 28 will be configured to compress in thickness, when installed.Preferred materials for the seal 28 comprise foamed sealant materials,such as foam polyurethane, which can readily compress to form a strongseal. Useable polyurethane seal materials include those described inU.S. Pat. No. 6,350,291 and U.S. application Ser. No. 10/112,097, filedMar. 28, 2002, both of which are incorporated herein by reference,although alternatives are possible.

As described, the seal 28 is specifically an axial pinch seal (or axialhousing seal). It can be configured with relatively flat oppositesurfaces 28 a, 28 b, or with opposite surfaces that have a ridge orgroove therein. Alternate seals can be used, including radial seals.

In general surfaces 28 a, 28 b comprise housing engagement seal regions,since it is these regions that engage the housing, during sealing.

A useable method for generating this type of seal arrangement can beunderstood by reference to FIGS. 10, 10A, and 17 and the followingdescription. In FIG. 10, the media pack 26 is shown inserted into aninterior 60 a of preform 60. It would be understood, that the media pack26 would be positioned with core 76, projecting into the media pack 26,between media layers.

The assembly 95 comprising the shell 60 and media pack 26 are shownpositioned in mold arrangement 97. The mold arrangement 97 includes amold base 98 and a mold cover 99 defining cavity 100 therebetween. Thecavity 100 is configured for formation of the seal 28. The seal 28 isformed by dispensing a curable resin into mold cavity 100, preferablyafter assembly 95 is positioned in base 98 and before cover 99 is inplace. In operation, a foaming urethane (which preferably will increasein volume at least 20%, typically at least 40% and usually 50-100%during cure), would be used.

Before resin cure, the mold cover 99 would be put into position. Themold cover provides definition of a portion of seal 28. During molding,the resin will rise to fill cavity 100. This rise would generallyinvolve flow through apertures 66 in housing seal support 65, FIG. 9A.As a result of flow through these apertures, after cure the seal 28 willbe mechanically secured to the seal support 65, due to a portion of theresin being cured and left in extension through the apertures 66.

Sealing of a portion of the cured seal 28 directly to the media pack 26a will also occur at region 100, since in this region the resin willdirectly contact the media pack. Flow across end surface 23 willgenerally be prevented by sloped region 102 of the cavity 100 engagingin the media pack 26. If necessary to inhibit flash at this location,the media pack 26 can be pinched by the mold at this region; or, athixotropic bead can be placed between the media pack 26 and the moldbase 98 at this location.

Referring to FIG. 10A, at 103, the funnel surface 64 (FIG. 9B) of thepreform 60 creates a surface diagonal upwardly toward the media pack 26.This slope will help directed resin toward the media pack, and alsoinhibit trapping of air at this location during the molding process.

FIG. 17 illustrates an alternate embodiment of a method for generatingpreferred types of seal arrangements described herein. In FIG. 17, themedia pack 26 is shown inserted into an interior 360 a of a preform 360.The assembly 395 comprising the shell 360 and media pack 26 are shownpositioned in the mold arrangement 397. The mold arrangement 397includes a mold base 398 and a mold cover 399 defining a cavity 400therebetween. The cavity 400, in this embodiment, is shown filled withresin 401. The cavity 400 is configured for formation of the seal 28.The seal 28 is formed by dispensing a curable resin into the mold cavity400, preferably after the assembly 395 is positioned in the base 398 andbefore the cover 399 is in place. In operation, a foaming urethane wouldbe used. A foaming urethane would preferably increase in volume at least20%, typically at least 40%, and usually 50%-100% during cure.

Before the resin cures, the mold cover 399 would be put into position onthe base 398. The mold cover 399 provides definition of a portion ofseal 28. During molding, the resin will rise to fill cavity 400. Thisrise would generally involve flowing through apertures 66 in the housingseal support 65 (FIG. 9 a). As a result of flowing through theseapertures, after curing, the seal 28 will be mechanically secured to theseal support 65, due to a portion of the resin being cured and left inextension through the apertures 66.

Thus, advantageously, the seal 28 (FIG. 8) for arrangements according tothe present disclosure provide for both: a housing seal portions asindicated at 28 a, 28 b as opposite surfaces for sealing with a housingin use; and, a portion 28 c, integral with the housing seal portion 28a, which provides for: a seal directly to the media 26; a seal aroundthe media pack 26; and, a seal of the media pack 26 and the preform 60,360 (or 25 a). These seal portions (28 a, 28 b, 28 c) are preferablyintegral with one another and are simultaneously molded from a singleresin shot. By “integral” in this context, it is meant preferablyregions 28 a, 28 b, 28 c are all portions of the same cure or pool orvolume of resin, without separation therebetween. This is preferred, forconvenient assembly without multiple sealing steps.

Referring to FIG. 8, the preferred shape of the seal 28 includes portion28 d directed upwardly (toward end 23) from surface 28 a; with portion28 e oppositely directed, to fill in a region between funnel surface 64and media pack 26. Regions 28 a and 28 b are positioned at oppositesides of lip 65, with transition portion 28 f preferably positioned toextend therebetween.

Angle A, the acute angle between media pack 26 and funnel surface 64preferably extends at an angle A within the range of 30° to 60°inclusive, more preferably 35° to 55° inclusive.

This type of molding operation uses some principles related to thatdescribed in U.S. provisional application 60/532,783 filed Dec. 22,2003, the complete disclosure of which is incorporated herein byreference. Some of the techniques used in that application can beapplied to provide for the seal arrangement shown in FIG. 8. It is notedthat the particular location and shape of the present FIG. 8 seal isquite different, as well as the location and nature of the preform pieceused. Further the specific example seals shown are of different typeswith respect to how the housing is preferably engaged.

Although the media packs can be made in a variety of sizes and shapes, atypical media pack useable in the specific configurations depicted, willhave an axial length of at least 140 mm, and a longer cross-sectionallength axis of at least 190 mm and a shorter cross-section axis orlength of at least 110 mm.

Referring to FIG. 8, generally the interface between media pack 26 andseal material of seal 28, is over a distance of extension along themedia pack of at least 4 mm, and typically 5-15 mm. This extension helpsprovide for a good secure engagement between the media pack 26 and theseal 28. Further the seal 28, will operate for some dampening affectwith respect to vibration, of the equipment on which the assembly 1 isinstalled, being transmitted undesirably to the media pack 26potentially damaging the media pack 26 at this location. That is, thedesirable dampening effect of the material 28 facilitates integrity ofthe filter cartridge 22, during use.

C. Usable Safety Filters

In reference now to FIGS. 11-14, an embodiment of a usable safety filter20 is illustrated. In preferred systems, the safety filter 20 isoriented in the air cleaner 1 downstream of the primary filter cartridge22 in order to protect downstream components from debris that could getpassed the primary filter cartridge 22, in case of failure of theprimary filter cartridge 22. In addition, the safety filter 20 helps toprotect the engine while servicing the air cleaner 1 while preventingdebris from falling into clean air region 32, FIG. 4.

The safety filter 20 has an outside periphery 170 that preferablymatches, in general shape, the outside periphery of the primary filtercartridge 22. In the embodiment illustrated, the safety filter 20 isobround, but can be other shapes such as circular. The particularobround shape shown is a racetrack shape with a pair of opposite sides172, 173, joined by a pair of rounded or curved, opposite, ends 174,175.

In the illustrated embodiment, the safety filter 20 includes a rigid,structural frame 178. Forming a portion of the frame 178 is a skirt orband 180. The band 180 circumscribes an internal region of filter media184. A variety of types of media 184 can be utilized. In theconfiguration shown, the media 184 is pleated, with the pleats 185, FIG.11, extending parallel to the straight sides 172, 173. Pleat densitiesof at least two pleats per inch, and typically 3-8 pleats per inch, areuseable, for example. In FIG. 11, it can be seen how there are tworegions of pleats 186, 187. The first pleat region 186 is separated fromthe second pleat region 187 by a partition 188 of the frame 178 thatgenerally bisects the safety filter 20. The bisecting wall 188 extendslongitudinally along the safety filter 20 between curved end 174 andcurved end 175.

In the preferred embodiment, the safety filter 20 includes a handle 190that is sized to accommodate at least a portion of a human hand. By“sized to accommodate a portion of a human hand”, it is meant that thehandle 190 has structure between it and the remaining portion of thesafety element 20 that allows at least a part of hand (a finger orfingers) to fit between the handle structure and the remaining portionof the safety filter 20 to allow for manipulation of the safety filter20.

In the embodiment shown, the safety filter 20 includes the handle 190projecting from the frame 178. In preferred embodiments, the handle 190is an integral extension of the partition 188. A variety of handleconstructions 190 are usable. In the one shown, the handle 190 has atleast one projection 192 extending from the frame member 189. Theprojection 192 can take various configurations, including knobs, rings,extensions, etc. In the one shown, the projection 192 takes the form ofan arm 194 defining a void 196, FIG. 12. In preferred embodiments, thevoid 196 goes completely through the arm 194.

In particular preferred embodiments, the handle 190 includes a secondprojection 198. The second projection 198 can also take a variety ofshapes or configurations. In the one shown, the projection 198 has thesame shape as projection 192, in the form of an arm 202 having a void204 (FIG. 12) therebetween.

The sizes of the voids 196, 204, in preferred embodiments, are largeenough to accommodate a gloved finger of a human hand, to assist withmanipulation of the safety element relative to the air cleaner 1. Forexample, the voids 196, 204 define a cross-sectional area of at least 2cm², typically 4-100 sq. cm². The projections 192, 198 are separatedfrom each other by a landing 206, FIG. 12, in the partition 188.

In preferred uses, volume 205 defined by landing 206 and the inner sides207, 208 of each projection 192, 198 accommodates the apex 152 (FIG. 7)of the centering construction 79 of the core 57, see FIG. 4. In suchpreferred uses, the projections 192, 198 operate as guides 212, 214(FIG. 12) to help operably orient the primary filter cartridge 22 inplace in the air cleaner 1. The guides 212, 214, can be sized to help tocenter and place the filter cartridge 22 within the air cleaner 1.

Still in reference to FIGS. 11-14, the preferred safety filter 20includes a seal member 218 to help form a seal 220 (FIG. 4) between thesafety filter 20 and the air cleaner section 9 of the housing 2. In theone shown, the seal member 218 is secured to the band 180 around theentire periphery of the band 180. The seal member 218, in the one shown,forms a radially directed seal 221 (FIG. 4) between and against the band180 and the inside surface 120 of the air cleaner section 9 of thehousing 2.

Useful media 184 can include many different types of conventional filtermedia. This includes cellulose, synthetic, and various blends. Oneusable, convenient media is a synthetic/glass fiber blend having aweight of 70±4.0 lb./3,000 ft.² (114±6.5 g/m²); a thickness of0.032±0.003 in (0.81±0.08 mm); a Frazier permeability of 165±20 ft./min.(50.3±6.1 m/min.); a pore size of 100±8 microns; a dry tensile strengthof 19.8±6.6 lb./in (9.0±3 kg/in); and a burst strength of 20±5 psi(138±34 kPa).

D. Usable Precleaner Constructions

In FIGS. 2-4, a preferred precleaner section 8 is illustrated. While anumber of different, conventional precleaners can be used upstream ofthe primary filter element 22, the particular precleaner 8 illustratedcan be used to advantage.

As mentioned above, the precleaner 8 includes a plurality of centrifugalseparator tubes 13, FIG. 2A. Each of the tubes 13 include an outersurrounding substantially cylindrical wall 228 that is tapered betweenopposite ends 229, 230. The end 229 has a smaller diameter than the end230. The end 229 will be oriented upstream to the end 230. Locatedwithin the wall 228 is a vortex generator 232, FIG. 3, including vanesor curved blades 234. The wall 228 also includes at its downstream end230 an outlet port 236, FIG. 2A.

Each of the tubes 13 is received within an upstream baffle plate 238,FIG. 2A. The baffle plate 238 includes a plurality of apertures 240sized to receive the upstream end 229 of the tubes 13. The upstream end229 of each of the tubes has a tab 242 (FIG. 3) that is received withina slot 244, FIG. 2A, which is part of the aperture 240. Thistab/aperture forms an indexing arrangement 246 (FIG. 3) that ensuresthat each of the outlet ports 236 on each of the tubes 13 is pointed inthe direction toward the dust ejection tube 4.

The preferred precleaner 8 depicted also includes a plurality ofextraction tubes 250, FIG. 4, that are received within the tubes 228. Inpreferred implementations, each of the extraction tubes 250 is molded asan integral part of the cover 7. As such, in preferred embodiments, thecover 7 includes as an integral, molded, one-piece member: the side wall252, the tube 14, a downstream baffle plate 254, and each of theextraction tubes 250.

To assemble the precleaner 8, each of the tubes 228 is inserted into acorresponding aperture 240 in the baffle plate 238. The indexingarrangement 246 is used by aligning the tab of each of the tubes 228into a corresponding slot 244 to ensure that the outlet port 236 ispointed in a direction toward the ejector tube 4. The upstream baffleplate 238 with each of the tubes 228 installed there within is thenoriented over the remaining portion of the precleaner 8. Each of theends 230 of the tubes 228 is oriented over a corresponding extractiontube 250, and the baffle plate 238 is secured, such as by a snap fit,onto the side wall 252.

The precleaner 8 operates as follows: a gas flow stream containingparticulate matter flows through the upstream end 229 of each of thetubes 13. The flow is induced to rotate by the vortex generator 232. Therotating nature of the flow stream causes centrifugal forces to act onthe particulate matter in the gas flow stream. The particulate matterheavier than the gas in the flow stream and migrates toward the wall228.

The particles are ejected from the outlet ports 236, while the remaininggas stream flows through the extraction tubes 250. From the extractiontubes 250, the air flows downstream and into the upstream flow face 23of the primary filter element 22. The particulate matter that is ejectedfrom the outlet ports 236 falls by gravity downwardly through theejection tube 4 and out through the ejection valve 15.

E. Methods

In general, a method of sealing a filter element having a straightthrough flow construction, as described, is provided. The preferredmethod generally includes positioning opposing flanges of a cover and aprimary air cleaner section, as described, in engagement with theprojecting axial seal gasket (on the element) and axially compressingthe gasket, as shown.

A method for mounting a sealing gasket in a filter cartridge having astraight through flow construction, as described, is provided. Oneexample method generally includes sealing a preform and media packtogether, with the same seal material shot that will form a housing sealfor the cartridge.

To clean gas, first, the filters (20, 22) should be installed within theair cleaner 1. The cover 8, containing a precleaner, is removed from theair cleaner section 9 of the housing 2. The safety filter 20 isprovided. The safety filter 20 is handled and manipulated by graspingthe handle 190, such as putting fingers through the voids 196, 204. Thesafety filter 20 is placed through the open end of the air cleanersection 9 and installed within the portion 32. The gasket 220 iscompressed between and against the wall 9 to form a radial seal 221between the safety filter 20 and the air cleaner section 9.

Referring to FIG. 4, next, the primary filter cartridge 22 is provided.The primary filter cartridge 22 is manipulated such that the downstreamend 24 is placed first through the open end of the air cleaner portion9. The receiver 75 is aligned with the guides 212, 214 to be receivedtherein. In particular, the core 57 has receiver pockets 164, 167, FIG.4, that receive the guides 212, 214 there within. The centeringstructure 152 of the core 57 interacts with the guides 212, 214 to helpalign and center the primary element 22 within the air cleaner section9.

The primary filter cartridge 22 is centered as described above andoriented such that the gasket 28 rests upon the flange 371 of the aircleaner section 9. Next, the precleaner section 7 is oriented over theair cleaner section 9 so that the flange 370 rests on the gasket 28. Theover center latches or clamps 17 are then used to apply axial force atjoint 11 and form an axial seal with the gasket 28 between theprecleaner section 7 of the housing and the air cleaner section 9 of thehousing. Flange 370 includes peripheral extension 370 a, FIG. 8, tocover outer annular portion 28 f of seal 28.

To clean air, the air enters the precleaner 7 through the centrifugaltubes 13. The vortex generator 232 causes the gas flow to rotate, whichcauses the particulate matter to migrate toward the walls 228. Theparticulate matter is then ejected through the outlet ports 236, to fallby gravity through the dust ejector tube 14. The precleaned air thenflows through the extraction tubes 250 and then through the inlet face23 of the primary filter element 22. The media pack 26 removes furtherparticulate material from the air. The cleaned air then flows throughthe outlet face 24. Next, the cleaned air flows through the media 184 ofthe optional safety filter 20, and then through the outlet tube 3. Fromthere, the cleaned air flows to downstream equipment, such as an engine.

After a period of use, the air cleaner 1 will require servicing. Toservice the air cleaner 1, the precleaner section 7 is removed from theair cleaner section 9 of the housing 2. This is done by releasing theclamps. When the clamps 17 are released, this releases the axial sealformed by the sealing gasket 28. The upstream face of the filtercartridge 22 is then exposed. The filter cartridge 22 is grasped andremoved from the air cleaner section 9. The primary filter cartridge 22can be disposed of or recycled, in convenient applications. If thesafety filter 20 also needs servicing, the handle 190 is grasped, andthe safety element 20 is removed from the air cleaner section 9 anddisposed of or recycled. It should be understood that in manyapplications, the primary filter cartridge 22 will require replacement,while the safety filter element 20 will not require replacement.

If the safety filter 20 is being replaced, then a second, new safetyfilter element 20 is inserted into the housing 2, as described in theinitial installation description above. Next, a new primary filtercartridge 22 is provided and is installed within the air cleaner section9, as described above. The precleaner section 8 is placed over the aircleaner section 9, and the axial seal is formed with the gasket 28.

What is claimed is:
 1. An air filter cartridge comprising: (a) a mediapack comprising a fluted media sheet secured to a facing media sheet,the media pack having an inlet flow face, an outlet flow face, and anaxial length between the inlet flow face and the outlet flow face,wherein the media is closed to the flow of unfiltered air therethrough;(b) a preform having a sidewall portion circumscribing the media packand including a seal support, wherein the media pack is secured withinthe preform; and, the preform includes a plurality of aperturestherethrough in a portion of the preform surrounding the media pack; (c)a seal arrangement secured on the seal support; and (d) the media packhas a cross section with a pair of opposite sides joined by a pair ofcurved opposite ends.
 2. An air filter cartridge according to claim 1,wherein the preform comprises a molded plastic material.
 3. An airfilter cartridge according to claim 1, wherein the seal arrangementcomprises foam polyurethane.
 4. An air filter cartridge according toclaim 1, wherein the preform is secured to the media pack by the sealarrangement.
 5. An air filter cartridge according to claim 1, whereinthe seal arrangement is constructed to provide an axial seal when insealing engagement with an air cleaner housing.
 6. An air filtercartridge according to claim 1, wherein the media pack comprises acoiled media pack.
 7. An air filter cartridge according to claim 1,wherein the preform includes a portion extending over one of the mediapack flow faces.
 8. An air filter cartridge according to claim 1,wherein the preform includes a portion extending over the outlet flowface of the media pack.
 9. An air filter cartridge according to claim 7,wherein the portion extending over one of the pack flow faces comprisesa grid work.
 10. An air filter cartridge according to claim 9, whereinthe grid work comprises diagonal cross pieces.
 11. An air filtercartridge according to claim 9, wherein the grid work inhibits mediatelescoping.
 12. An air filter cartridge according to claim 1, whereinthe preform further comprises a funnel surface extending at an anglerelative to the media pack.
 13. An air filter cartridge according toclaim 12, wherein the angle is within the range of 30° to 60°.
 14. Anair filter cartridge according to claim 12, wherein the angle is withinthe range of 35° to 55°.
 15. An air filter cartridge according to claim1, wherein: (a) the plurality of apertures in the preform are seal flowapertures; and, (b) the seal arrangement is molded to the seal supportand extends through the seal flow apertures.
 16. An air filter cartridgecomprising: (a) a media pack having a first end, a second end, and anaxial length between the first end and the second end, wherein the mediais closed to the flow of unfiltered air therethrough; (b) a preformhaving a sidewall portion circumscribing the media pack and including aseal support, wherein the media pack is secured within the preform; and,the preform includes a plurality of apertures therethrough in a portionof the preform surrounding the media pack; (c) a seal arrangementsecured on the seal support; and (d) the media pack has a cross sectionwith a pair of opposite sides joined by a pair of curved opposite ends.17. An air filter cartridge according to claim 16, wherein the preformcomprises molded plastic.
 18. An air filter cartridge according to claim16, wherein the seal arrangement comprises foam polyurethane.
 19. An airfilter cartridge according to claim 16, wherein the preform is securedto the media pack by the seal arrangement.
 20. An air filter cartridgeaccording to claim 16, wherein the seal arrangement is constructed toprovide an axial seal when in sealing engagement with an air cleanerhousing.
 21. An air filter cartridge according to claim 16, wherein: (a)the media pack comprises fluted media secured to facing media anddefining an inlet flow face and an outlet flow face, at the first endand second end respectively.
 22. An air filter cartridge according toclaim 21, wherein the media pack comprises a coiled media pack.
 23. Anair filter cartridge according to claim 21, wherein the preform includesa portion extending over one of the flow faces.
 24. An air filtercartridge according to claim 23, wherein the preform includes a portionextending over the outlet flow face.
 25. An air filter cartridgeaccording to claim 23, wherein the portion extending over one of theflow face comprises grid work.
 26. An air filter cartridge according toclaim 25, wherein the grid work comprises diagonal cross pieces.
 27. Anair filter cartridge according to claim 25, wherein the grid workinhibits media telescoping.
 28. An air filter cartridge according toclaim 17, wherein the preform further comprises a funnel surfaceextending at an angle relative to the media pack.
 29. An air filtercartridge according to claim 28, wherein the angle is within the rangeof 30° to 60°.
 30. An air filter cartridge according to claim 28,wherein the angle is within the range of 35° to 55°.
 31. An air filtercartridge according to claim 17, wherein (a) the seal arrangement ismolded to the seal support and includes portions extending through theplurality of apertures.
 32. An air cleaner assembly comprising: (a) ahousing having a primary air cleaner section, and a cover; (i) thehousing being jointed between the cover and the primary air cleanersection; and, (b) an air filter cartridge positioned within the housing;the air filter cartridge comprising: (i) a media pack comprising afluted media sheet secured to a facing media sheet, the media packhaving an inlet flow face, an outlet flow face, and an axial lengthbetween the inlet flow face and the outlet flow face, wherein the mediais closed to the flow of unfiltered air therethrough; (ii) a preformhaving a sidewall portion circumscribing the media pack and including aseal support, wherein the media pack is secured within the preform; and,the preform includes a plurality of apertures therethrough in a portionof the preform surrounding the media pack; (iii) a seal arrangementsecured on the seal support; and (iv) the media pack having a crosssection with a pair of opposite sides joined by a pair of curvedopposite ends.